Check-valve



(No Model.)

G. F. BLAKE.

UHF-GK VALVE.

Patented Jan.16,'1883.

Wi'fiwsses.

WfH ML/M Uwrre TATES GEORGE F. BLAKE, OF BELMONT, MASSACHUSETTS.

CH E'CKQ-AVALVE.

SPECIFICATION forming part of Letters Patent No 270,573, dated January 16, 1883.

Application filed September 26, 1882. (No model.)

To all whom it may concern:

3e it known that I, GEORGE F. BLAKE, of Belmont, county of Middlesex, State of Massachusetts, have invented an Improvement in Check-Valves, of which the following descripfail to maintain the pressure in the exhaustpipe below that of the atmosphere, or when it is desired to run the engine non-condensing.

The object of my invention is to preventthe valve from hammeringits seat; and. it consists partly in the combination, with the valve and its seat, of a piston connected with the valvestem, and a cylinder therefor connected with the interior of the valve-casing. The upper end of the cylinder referred to opens directly into the valve-casing, and the lower end thereof is closed. The piston on the valve-stem fits loosely in the cylinder, and is provided with a small passagecontrolled by a downwardlyopening valve, which permits the water of condensation collected in the lower part of the valve-case to pass down into the cylinder below the piston when the valve is raised from its seat, and the said water in the cylinder retards themovement of the valve as it returns to its seat, preventing concussion,the water below the piston having its only exit between the cylinder and piston.

Figure lis avertical longitudinal section of a valve embodying this invention; Fig. 2, an

under side view ofthe piston at the end of the valve-stem and Fig. 3, a diagram illustrating, in plan view, the relation of the valve to the exhaust-passages of the engine.

The casing A, having inlet and outlet openings 2 3, and a partition, a, between them provided with the valve port and seat I), may be of any suitable or usual construction, it being shown in this instance as provided with a removable cover or bonnet, c; for the insertion of the valve (1, the upper portion of the stem 6 of which travels in a guide,f, attached to the said bonnet c.

The lower portion of the casing" A is provided with a cylinder or daslrpot, g, shown as made in a separate piece, having a flange, h, for attaching it to the said casing, which has a suitable opening to receive it, the said cylinder being closed at its lower end and opening directly into the casing A at its upper end. The lower end of the valve-stem has connected therewith a piston or plunger, i, loosely fitted in the cylinder g, and provided with a small passage, k, controlled by a valve, m, shown as consisting of a flexible strip of metal, opening downward, to permit a free passage of fluid through the opening k from the interior of the casing A into the cylinder 9 below the piston, but preventing the flow thereof in the opposite direction. The cylinder 9 may be cast-in one piece with the casing A.

In operation the valve is intended to be placed, as shown in Fig. 3, in the outboard exhaust-pipe n, or pipe leading from the exhaust-pipe 0, that connects the engine and condenser, into the atmosphere, so that the pressure of the atmosphere will act on the valve 01 to seat it, except when the exhaust-pressure acting'on the under side of the valve d is greater. The lower portion of thecasing A will become filled with water of condensation, and when the pressure of the exhaust exceeds that of theatmosphere it will raise the valve cl. Atthe same time the pressureabove the piston i will open the valve on and cause the said water to flow through the passage k and fill the cylinder 9 below the said piston i. If the pressure of the exhaust is suddenly diminished, the "alve d is closed by its own weight and the pressure of the atmosphere; but the downward movement is checked by water in the cylinder 9 beneath the piston c, which permits the said movement to take place only as fast as the water can escape from the cylinder around the piston, the water thus retarding the downward movement and preventing concaused hyits being hammered by the valvecan be prevented.

By locating the valve-seat, as shown,b etween the valve and piston, and having the valve seat downwardly upon itsupper surface, the

movement of the valve in seating is positively resisted by the fluid entrapped beneath the piston, the said movement; taking place only as fast as the liquid can escape around the piston.

I am aware that previous to this invention valves have been controlled in their seating movement by a connected piston operated in a cylinder connected with the valve-casing, and do not broadly claim such construction.

I claim- 1. The "alve-casing and valve-seat therein,

and the valve seating on the upper surface of the said valve-seat, and the piston connected with the said valve, combined with the cylinder or dash-pot, co-operating with the said piston and openinginto the said valve-casing, 

